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Biomedical subjects

A Castaigne

Publications and source records attributed to A Castaigne.

At least 127 records · Page 7Linked to original sources
PubMed1990

MIBG scintigraphic assessment of cardiac adrenergic activity in response to altitude hypoxia.

High altitude hypoxia induces a decrease in the cardiac chronotropic function at maximal exercise or in response to isoproterenol infusion, suggesting an alteration in the cardiac sympathetic activation. Iodine-123 metaiodobenzylguanidine [( 123I]MIBG) was used to map scintigraphically the cardiac sympathetic neuronal function in six male subjects (aged 32 +/- 7 yr) after an exposure to high altitude that created hypoxic conditions. Results obtained just after return to sea level (RSL) were compared with the normal values obtained after 2 or 3 mo of normoxia (N). A static image was created as the sum of the 16-EKG gated images recorded for 10 min in the anterior view of the chest at 20, 60, 120, and 240 min after injection. Regions of interest were located over the heart (H), lungs (L), and mediastinum (M) regions. There was a significant decrease in the H/M and the L/M ratios in RSL compared to N condition. Plasma norepinephrine concentration was elevated during the stay at altitude but not significantly different in RSL compared to N. In conclusion, cardiac [123I]MIBG uptake is reduced after an exposure to altitude hypoxia, supporting the hypothesis of an hypoxia-induced reduction of adrenergic neurotransmitter reserve in the myocardium. Furthermore, the observed significant decrease in pulmonary MIBG uptake suggests an alteration of endothelial cell function after exposure to chronic hypoxia.

3-Iodobenzylguanidine↗
PubMed1989

[Platelet antiaggregants and coronary pathology].

Platelet inhibitors have widely been studied in various clinical situations resulting from atherosclerosis of the coronary arteries. At present, aspirin is virtually the only drug that has proved to be effective in all cases where the risk of coronary thrombosis was very high. Administered in daily doses of 160 to 1,500 mg, acetylsalicylic acid reduces the frequency of coronary thrombosis and its consequence, myocardial infarction, in the following clinical situations: year following myocardial infarction, acute phase of myocardial infarction, unstable angina, year following aorto-coronary bypass, days following dilatation of the coronary arteries. Acetylsalicylic acid has been compared with heparin and anti-vitamin K agents in four trial: whatever the model studied, no difference was found in the effectiveness of the two treatments tested. Aspirin ha recently been reported as preventing myocardial infarction in healthy subjects. The practical value of this finding is questionable. The various effects of aspirin have been ascribed to the fact that it interrupts a cascade of events ranging from rupture of atherosclerosis plaques to arterial thrombosis.

Angina, Unstable↗
PubMed1989

Pharmacological bridge to cardiac transplantation.

From September 1985 to August 1988, 32 patients were referred from various intensive care units throughout Paris for urgent cardiac transplantation or for a mechanical bridge to transplantation. At time of admission, under maximal sympathomimetic therapy, the cardiac index (CI) was 1.81 +/- 0.26 l/min per m2, the pulmonary capillary wedge pressure (PCWP 31 +/- 7 mmHg), systemic vascular resistances (SVR) 2053 +/- 469 dynes s cm-5. In 25, diuresis was less than 25 ml/h. Five were anuric. Prior to any final decision, a new inotropic agent, enoximone, was infused in addition to previous treatment as a 10 min bolus iv 1.5-2 mg/kg every 8 h. In 3, the situation further deteriorated, leading to a Jarvik 7-70 implantation within 12 h. In 29 however, within 3 h, the Cl increased to 2.69 +/- 0.56 as SVR dropped to 1410 +/- 453 and PCWP to 18 +/- 7. Diuresis increased to more than 100 ml/h in all. This permitted an indepth evaluation of the transplant candidates leading to contraindications to transplantation in 16. Nine patients could be weaned off iv enoximone. Four of these are still living (NYHA class III) with a follow up of 6-17 months. In 11, transplantation was performed within 2 days. Four died within a month, 2 with multiple organ failure. One patient died after 5 months. Six are back to normal life, NYHA class I (follow up 10 months-2.5 years). This protocol suggests that in patients with extreme heart failure, immediate survival may be increased by iv enoximone therapy, permitting a better selection of the recipients, more efficient pre-transplantation intensive care and consequently a decrease in the indications for a temporary mechanical bridge to a staged transplantation.

Adenosine Monophosphate↗
PubMed1989

Abnormalities in myocardial segmental wall motion during lumbar epidural anesthesia.

The effect of lumbar epidural anesthesia on myocardial wall motion was compared in two groups of patients using precordial two-dimensional echocardiography (2DE). All patients were scheduled to undergo lower abdominal or peripheral surgery. Group 1 included five healthy ASA PS 1 subjects and group 2 included 10 patients with coronary artery disease (CAD). In all patients 12.5 ml of 2% lidocaine HCl was injected into the lumbar epidural space, and systolic and diastolic blood pressures, and heart rate were continuously monitored. 2DE evaluation was performed before and at 10, 20, 30, and 60 min (T10-T60) after epidural lidocaine injection. The left ventricular wall was divided into 16 segments for parasternal long-axis, short-axis and apical four-chamber views. The wall motion of each segment was graded on a scale from 1 (dyskinesia) to 6 (hyperkinesia), with 5 representing normal motion. A decrease in segmental wall motion greater than or equal to 2 grades was considered indicative of ischemia. Plasma lidocaine and catecholamine levels were measured before and 10, 20, and 60 min after epidural lidocaine injection. Peak plasma lidocaine levels in groups 1 and 2 were 2.79 +/- 1.06 micrograms/ml (mean +/- SD) and 2.58 +/- 1.48 micrograms/ml at 10 min, respectively (NS). Plasma epinephrine and norepinephrine levels were unchanged from baseline. Systolic pressures decreased significantly in group 2 from T10 to T60. Diastolic pressure decreased significantly in the same group from T20 to T60, and in group 1 only at T10. Mean arterial pressure decreased significantly in both groups at T30, without change in heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Socioeconomic implications of the practice of thrombolysis in the acute stage of myocardial infarction].

The use of variegated and costly thrombolytic agents for the treatment of myocardial infarction in its acute phase may have medico-social advantages. In the present study, these advantages were evaluated after one year from two age and sex matched populations: 40 patients who underwent thrombolysis and 38 patients who did not. Compared with the first hospitalizations, the difference was + 4,000 francs, rising to + 11.000 francs with the drug Eminase. A questionnaire including medical, social and economic data was sent to the 78 patients and was filled by 63 of them, remaining unanswered by one patient who had thrombolysis and 10 patients who did not. Readmission to hospital showed a 44.000 francs difference to the benefit of patients who underwent thrombolysis. Ancillary care and return to work were similar in both groups. Cost expectancy was 119.500 francs for patients who had thrombolysis and 122.000 francs for those who did not. Thrombolysis therefore is a cost reduction factor, but its influence on costs is less pronounced when it is performed soon after the onset of myocardial infarction. Thrombolysis is more expensive when carried out at home than in hospital. In this study, the excess cost (+ 5.000 francs) was due to the relatively small number of patients and to the loss of professional activity which may be an uncertain factor. Mortality at one year was nil when thrombolysis was performed within the first two hours (12 patients) and rose to 16.6 percent between 2 and 3 hours (18 patients) and 30 percent after 3 hours (10 patients). Conducted on a necessarily limited number of patients, this multiple criteria study was also aimed at establishing a method to evaluate the health expenditures imposed by the introduction of new and costly treatment in the management of myocardial infarction.

Adult↗
PubMed1989

[Physiopathologic basis of the use of thrombolytic agents during the acute phase of myocardial infarction].

Experimental animal studies have shown that coronary occlusion is followed by myocardial infarction and that coronary reperfusion can limit infarction size. Myocardial necrosis and the recovery of function are progressive phenomena in these animal models. Similarly, human myocardial infarction is caused by coronary occlusion and the size and severity of the infarct can be reduced by spontaneous or therapeutic coronary reperfusion. However, there are important differences between the animal models and clinical myocardial infarction. The results of randomised therapeutic trials of thrombolytic drugs show that the theoretical equation between reperfusion, myocardial protection and reduction of mortality has not yet been fully validated. This may be explained either by the fact that the intermediary criteria of assessment (patency at 90 minutes and ejection fraction at the 3rd week) have been badly chosen or by the fact that some of the therapeutic benefit of thrombolytics on mortality is not due to reperfusion or myocardial protection. The physiopathological rationale behind the use of thrombolytics in the acute phase of myocardial infarction is coronary reperfusion, but is reperfusion beneficial in all myocardial infarcts? What is or are the intermediary factors between reperfusion and the decrease in mortality? Is reperfusion the only benefit of thrombolysis? Clear answers to these questions are not yet available.

Animals↗
PubMed1989

[Prehospital thrombolysis. Evaluation of preliminary experiences at Val-de-Marne].

Benefits of thrombolysis have been shown to be greater when therapy is administered early, and this led us to consider the value of starting thrombolytic treatment in the patient's home. However, this implies the transfer of responsibility of patient management from the cardiologist to the physician in charge of the mobile emergency care team. A study was undertaken in the Val-de-Marne department to assess the benefits and risks of this therapeutic approach. The first phase was designed to evaluate the reliability of the emergency care team's diagnosis and the second phase of the study was a randomised double blind prehospital therapeutic trial of a thrombolytic agent, acylated streptokinase (intravenous bolus of 30 units in 4 minutes) against placebo. The nature of prehospital treatment was revealed on hospital admission and thrombolytic therapy was immediately given to those patients allocated to placebo at home providing the admitting cardiologist confirmed the indication. A total of 100 patients were included; 57 were allocated to thrombolytic therapy and 43 to placebo in the prehospital phase. The diagnosis of acute coronary insufficiency was confirmed in all cases and 97 p. 100 of patients had signs of acute myocardial infarction. No complications were attributable to prehospital administration of the thrombolytic. The average time gain in instituting treatment was 60 minutes. At control coronary angiography, 72 p. 100 of the coronary arteries thought to the responsible for the infarct were shown to be patent. The global left ventricular ejection fraction of patients treated with thrombolysis at home was 56.7 p. 100 compared with 53.4 p. 100 in the placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Ambulances↗
PubMed1989

[Early angioplasty in unstable angina. Results apropos of 60 consecutive patients].

Transluminal coronary angioplasty (TCA) is an attractive means of suppressing ischaemia in patients (pts) with unstable angina. Sixty consecutive pts underwent TCA 6 +/- 2.5 days on average after their admission. Only the ischaemic vessel was dilated (mean stenosis 79 p. 100). Primary success was obtained in 53 pts (88 p. 100) with 31 p. 100 of residual stenosis after TCA. Two pts underwent emergency surgery for extensive dissection; failure of traversing the stenotic segment occurred in 2 pts; 3 pts had myocardial infarction (MI) less than 1 h after TCA, 2 arteries have been recanalized by intracoronary streptokinase with persistence of a satisfactory result of TCA, the 3rd patient had occlusion of a secondary side branch. During their stay in hospital, 2 pts had coronary bypass for recurrent angina. After a follow-up period of 6 to 16 months (mean 10 months) early recurrence of angina was observed in a number of cases (before the sixth month in 7 pts). One pt developed MI during the fourth month. At six month, 10 or the initial 60 pts had undergone coronary bypass, 1 undilated pt was asymptomatic; out of 49 dilated pts (47 with one single TCA), 39 were symptom-free but 6 had a positive exercise test, 7 pts were in class II and one in class IV. At control coronary arteriography (46 pts) restenosis was present in 39 p. 100: 5 new TCA and 2 aorto-coronary bypasses were performed. At one year 28 pts had been followed up: 1 was in class IV and 1 in class II, the others being asymptomatic.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[6 months' results of coronary angioplasty after thrombolysis of myocardial infarction].

Transluminal coronary angioplasty (TCA) has become the treatment of choice of residual stenosis after thrombolysis for myocardial infarction, but the long-term results of TCA are imperfectly evaluated. Seventy patients underwent TCA after thrombolysis on account of a significant (greater than 50 p. 100) residual stenosis of the artery responsible for the infarction. TCA was performed less than 6 hours after the onset of symptoms in 15 patients who had neither clinical nor electrocardiographic evidence of reperfusion; 4 of these patients were in a state of cardiogenic shock. In the remaining patients TCA was performed 1 to 10 days (mean 3.2 days) after thrombolysis. A primary success was obtained in 64 patients (91 p. 100). Two patients had emergency aorto-coronary bypass. During their stay in hospital, 5 patients presented with symptoms of reocclusion which in 4 of them occurred less than 24 hours after TAC, and 2 of these 4 patients had to be reoperated upon; 2 patients died suddenly. During a 6 to 18 months' follow-up period (mean 10.5 months), the infarction recurred in 3 patients; the recurrence took place during the 3rd month in 2 of them (1 had another thrombolysis and later TAC) and during the 6th month in the third one. At 6 months, 4 patients were suffering from exertion angina and 2 asymptomatic patients had a positive exercise test. Fifty-two control coronary arteriographies were performed at 6 months. Thirteen patients (25 p. 100) had an occluded artery which was clinically silent in 11; 39 patients had a patent artery with restenosis in 7.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗